<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>首页</title>
</head>
<body>
  <form action="/post" method="POST">
    用户名：<input type="text" name="username" required minlength="2" maxlength="5">
    密码：<input type="password" name="psd" required minlength="6" maxlength="10">
    <input type="submit" value="提交">
  </form>
</body>
</html>